How to fight cow farts and save the world

We all know about global warming, and we all want to save the planet. The average person on the planet is responsible for about four tons of carbon dioxide emissions per year, for a total of about 25 gigatons (thousand billion tons) (http://timeforchange.org/CO2-emissions-by-country). Seems like a lot.

Surprisingly, however, although it gets almost all of the press, maybe carbon dioxide emissions aren’t the biggest problem. Consider the cow, which burps and farts huge quantities of methane, a much more powerful greenhouse gas than carbon dioxide.

A United Nations report concluded that “the livestock sector generates more greenhouse gas emissions as measured in carbon dioxide equivalent than transport.” (http://change.nature.org/2011/04/01/no-fooling-cow-burps-and-farts-contribute-to-climate-change/) Yes, eating those MacBurgers might be worse for the environment than driving that SUV. As Robin says to Batman, “Holy Cow!”

To better understand the problem we have to dig deep into the bowels of the subject. Amazingly, it turns out that people have about ten times more bacterial cells than human cells. What?? Yes, it is true (http://www.sciencedaily.com/releases/2008/06/080603085914.htm). Bacterial cells are very small, and our guts are crammed full of them. So, in the end, each of us actually has far more bacterial cells than people cells. The same sort of ratio is also true for cows. Like us, they are loaded with bacteria.

And therein lies the rub. The bacteria are very useful for the cows, converting otherwise worthless plant material into functional food. Unfortunately this fermentation process creates methane. A quick look at the fart chart shows that California tops the list, producing about 350,000 tons of methane a year, with Wisconsin coming in at number two (http://milk.procon.org/view.resource.php?resourceID=001154#methodology).

And how can we solve this problem? Researchers in Argentina have connected gas bags to cows, finding that each one produces around a thousand liters a day http://www.dailymail.co.uk/sciencetech/article-1033656/Reducing-cow-burping-key-tackling-climate-change.html. If we could only harvest this energy source to power our cities! Alas, this seems unlikely.

Some studies have suggested that a change of diet could help. Less Mexican and more Beano? Or, maybe just more alfalfa and clover.

Of course one option would be for us all to go vegan. Just stop eating cows and drinking their milk. There are some reasons to think this might be the best route. Cows are mammals like us, and have almost the same set of genes. From an evolutionary perspective eating a cow is sort of like eating your cousin. But, darn it, they taste so good!

Thank heaven there has recently been a major breakthrough in cow fart research. It turns out that kangaroos are relatively methane free. So maybe we should kill the cows and switch to roos. But there could be some nasty consequences. Imagine enormous numbers of kangaroos jumping over fences, crashing into cars, and creating massive carnage. No, there must be a better way.

It turns out that marsupials have different bacteria in their guts, that produce succinate as a by product instead of methane (http://news.sciencemag.org/sciencenow/2011/06/scienceshot-why-wallabies-dont.html?etoc&elq=5629ef59290a47bd9fa324c28c66377c). So all we need to do is convert the population of bacteria in the cow gut over to the kangaroo type. We need a cow probiotic. The easiest way to do this would seem to be to collect a lot of kangaroo poop and spread it on the cow hay and see what happens.

In order to conduct these vital experiments I’m planning a roo poop collecting expedition to Australia. If you’d like to contribute, and thereby save the world, please mail me a check. Or, better yet, cash.

About the Author: Steve Potter, PhD, is a Professor of Pediatrics, in the Division of Developmental Biology, at Children’s Hospital Medical Center in Cincinnati. He has authored Designer Genes: A New Era in the Evolution of Man, published by Random House 2010 http://www.amazon.com/Designer-Genes-New-Era-Evolution/dp/140006905X/ref=sr_1_1?s=books&ie=UTF8&qid=1310842010&sr=1-1. In addition he has written over one hundred science papers, and co-authored the third edition of the medical school textbook, Larsen’s Human Embryology.

Is the Killing (Abortion) of Human Embryos Always Murder?

Dr. Robert Edwards won the Nobel Prize in 2010 for developing in vitro fertilization. The mixing of eggs and sperm in the test tube makes early human embryos, which can then be surgically placed in the uterus of the hopeful mother, where they develop into babies. This technology creates life, allowing otherwise infertile couples to bear children. About one percent of all births in the US are the result of in vitro fertilization. It also provides the foundation for the generation of designer genes babies, with pre-selected traits, and is therefore likely to become increasingly prevalent in the future.

But, in vitro fertilization results in hundreds of thousands of leftover embryos that are frozen indefinitely or discarded. Is the destruction of these early embryos, consisting of small clumps of cells, murder?

Early Human development takes place very slowly. The single cell that we all started from, the fertilized egg, divides once to make two cells, then again to make four, and once more to make a small cluster of eight cells. It takes a few days to get this far. And, amazingly, at this stage of development each of the eight cells is “totipotent”, or able to give rise to a complete and normal person if separated from the other cells. Accidental splitting of this clump is one way to make identical twins, triplets, etc.

A dictum of developmental biology is that “ontogeny recapitulates phylogeny”. This means that development of the individual reflects the evolution of its species. The Human embryo has a very long tail, and branchial arches that resemble gill slits. It first forms a primitive fish like kidney, which is later discarded and replaced with a mammalian kidney. Indeed, in many respects an early Human embryo more resembles a fish than a Human.

But, according to some, the embryo becomes a full person, with all rights, at the moment of conception, when the egg unites with the sperm. In some respects this is an attractive and clean answer. At this point there is the creation of a unique combination of genes that marks that individual and distinguishes it from all others. This is a physically well-defined event, setting apart those few eggs and sperm that do unite to form an embryo and then embark on the voyage of embryogenesis, to make a person.

There are, however, several arguments that suggest that the moment of conception is too early to confer full personhood. The fertilized egg has no beating heart, no brain, and no consciousness. It is not aware, it cannot think, and it cannot sense anything, including pleasure or pain. It is just two cells, the egg and sperm that have joined into one.

At the other end of life, when a person is old, sick and dying, we do have some established rules concerning when death has occurred, or when it is acceptable to “pull the plug”. Perhaps the same rules that apply to the end of life should be applied to the beginning. If the analysis of brain activity shows no conscious thought then life is considered over. This suggests that life begins with the formation of a brain and the initiation of conscious thought.

Then there is the question of the soul? It could be argued that while the fertilized egg has no brain, it nevertheless has a soul and is therefore a person. But if the early embryo has one soul, and then the embryo splits, do the resulting identical twins, triplets and so on only get a piece of the soul? And what about the reverse? Chimeras are people that look perfectly normal, but are the result of two early embryos fusing together to make one person. Do chimeras have two souls?

It is also interesting to note that there is an enormous natural loss of early Human embryos. The normal reproductive process is not very efficient. Only about half of Human fertilized eggs survive to birth. The vast majority of loss is very early, within the first few days after conception, and the mother never knew she was pregnant. This means that for every person alive, a total of about seven billion, there was a natural embryonic death. What a horrible holocaust, if we equate early embryonic life with that of an adult!

So, when is an embryo a person? The other extreme view might be at the moment of natural birth, when you enter the world and can breathe on your own. While some accept this view, for most it would be far too late. The vision of an abortion doctor strangling a late-stage abortus that is fighting for air is extremely repugnant. Clearly, when able to live outside of its mother given the support of available medical knowledge, with a functioning heart and brain, with pain and pleasure sensors, the baby in the mother is indeed a human being and deserving of the right to live.

Where do you draw the line? The one thing that is certain, is that there are no easy answers.

About the Author: Steve Potter, PhD, is a Professor of Pediatrics, in the Division of Developmental Biology, at Children’s Hospital Medical Center in Cincinnati. He has authored Designer Genes: A New Era in the Evolution of Man, published by Random House 2010 http://www.amazon.com/Designer-Genes-New-Era-Evolution/dp/140006905X/ref=sr_1_1?s=books&ie=UTF8&qid=1310842010&sr=1-1. In addition he has written over one hundred science papers, and co-authored the third edition of the medical school textbook, Larsen’s Human Embryology.

A Trip to the Creation “Science” Museum

Oh Boy. Oh Joy. I live in Cincinnati, home of the “Creation Museum”. In case you didn’t know, it is a “museum” dedicated to a literal interpretation of the bible. Earth is only a few thousand years old. God created all life on earth as we see it today. Evolution is wrong, never happened. The earth was completely flooded, and all land life would have perished, but for Noah’s Ark.

Down the highway, a few miles past the airport. Take the Petersburg exit and you’re there. It’s a Saturday afternoon and the parking lot is full. I quickly counted vans and buses from seven Baptist churches, one Methodist, the Junction City First Christian Church, and a couple of Christian schools. The kids are filing out of the cars and church vans, eager to enter, anxious to learn.

It isn’t cheap, twenty five bucks, and I hate to pay, but I’m curious. So I’ll pay, so you don’t have to. Let’s take the tour.

The place is packed and the moving slow. There is a large group of Amish. And another group of about 50 kids with tie dye T-shirts, with big blue crosses on their backs.

One of the first exhibits shows dinosaurs walking around with people. Sort of like Jurassic Park. But this is serious, not a novel. Of course the Bible tells us that all animals were vegetarians before Adam ate the apple. So why do some snakes have venom? We are told that maybe those nasty chemicals used to do something else when the snakes ate plants. And we learn that God gave the Tyrannosaurus Rex big teeth to crack nuts with. And what ended the dinosaurs? Why don’t we still see them today? Well, read on and find out.

Of interest, we see some nice fossils in the museum. But, the museum explains that the dating methods of science are flawed, and that none are really more than a few thousand years old.

Some of the exhibits were more two-sided than you would expect. For example, one shows Human Reason on the left side, starting with the Big Bang, followed by the evolution of galaxies, and solar systems, and the earth and moon, and the continents, all taking millions and billions of years. Then on the right side there is God’s Word, quoting Genesis, describing how God created earth and life in just six days, about six thousand years ago.

A thinking person walking through the museum might conclude that God’s word isn’t always very reasonable.

I was surprised, however, to see some serious concessions to science. For example there is a small exhibit showing a copy of a book by Charles Templeton, titled “Farewell to God”, and a quote saying that it is simply not possible to believe the biblical account of creation. And in a later exhibit I was shocked to see the following statements. “Natural selection is an observable process that occurs in the present.” “Natural selection is supported biblically and scientifically.” The museum actually supports the conclusion that one species can give rise to many through natural selection. But it somehow separates this from evolution by saying that there is no evidence for more dramatic events, like lizards giving rise to birds. Pretty interesting.

We also see pictures of great canyons, like the grand canyon. While science claims that it took millions of years to carve these out, the museum clarifies that these things can happen in a much shorter time through the power of floods.

And this brings us to the great flood. The museum is actually building a full size replica of Noah’s ark. You’d think it would have to be pretty big to carry all of the species we see on the planet today. It turns out there was no room for the dinosaurs. And how on earth did Noah get the kangaroos back to Australia? Maybe the ark made an extra stop not mentioned in the bible. Or, the museum suggests that before the flood there was only one continent, which then divided into several in the past few thousand years. Wow, pretty fast.

And what about those fresh water fish? If the oceans rose up to swallow the continent(s) then all of the lakes and rivers must have disappeared. And anyone with an aquarium knows that you can’t put fresh water fish in salt water. They die. So I think that maybe another lost section of the bible described how one floor of the ark was dedicated to fresh water aquaria to save the fish. I’m personally especially glad that Noah was able to save the Rocky Mountain trout.

The bible is quite a nice book. It sold a lot more copies than any of mine. There is some interesting history in there, and many fascinating stories. Maybe you like the God thing that it pushes, or maybe you don’t. But whatever your religious view, please, oh please, one thing that we can all be sure of, you should not take everything in the bible for literal truth.

About the Author: Steve Potter, PhD, is a Professor of Pediatrics, in the Division of Developmental Biology, at Children’s Hospital Medical Center in Cincinnati. He has authored Designer Genes: A New Era in the Evolution of Man, published by Random House 2010 http://www.amazon.com/Designer-Genes-New-Era-Evolution/dp/140006905X/ref=sr_1_1?s=books&ie=UTF8&qid=1310842010&sr=1-1. In addition he has written over one hundred science papers, and co-authored the third edition of the medical school textbook, Larsen’s Human Embryology.

 

Dogs Prove Evolution

Dogs provide an interesting proof of evolution. Consider the astonishing variety of different dog breeds. There is the tiny Chihuahua, about six inches tall and weighing under six pounds. And other dogs are enormous, with the Irish wolfhound rising above a person when on his hind legs, and the Saint Bernard weighing over two hundred pounds. Some dogs are extremely intelligent, including the border collie, retriever, poodle and German shepherd. These dogs learn new commands with ease, and can perform complicated tasks. Other dogs, however, seems very dimwitted, often requiring hundreds of repetitions to learn, and even then usually failing to obey a command. There is such an incredible assortment of different dogs that it is easy to forget that they are all the same species, Canis lupus familiaris. This means that even a Chihuahua and a Saint Bernard (assuming that the obvious physical challenges could be overcome) could mate and produce live and fertile offspring.

So where did dogs come from? Darwin thought they might come from multiple sources, including the wolf, jackal and coyote, thereby in part explaining their diversity. The DNA evidence, however, shows that they are all derived from the wolf. DNA from all dogs is over 99% identical to that of a wolf, while the wolf and coyote DNAs, for example, are over 4% different from each other. This means, surprisingly, that all of the diversity of dog types in the world today came from a single source, the wolf.

How did the wolf get transformed into a woof? The precise order of events is a matter of conjecture, but it probably began when an abandoned litter was taken in and nursed by people. The DNA evidence, which shows a strong similarity for all dogs, suggests that there might have only been only a few such domestication events. These early wolf dogs would be subjected to what is called artificial selection. In the wild natural selection is at work with the strongest, fastest and smartest wolves surviving better to make more wolves. But once under the care of people survival depends on a new set of rules. For example, animals that liked to bite people probably did not fare well. But dogs are natural hunters and could help in the search for food. They also could provide an early warning system, barking when unwelcome visitors approach. So people friendly watchdogs, with their heightened senses of hearing and smell, would be very useful to early humans.

People have selected dogs for a variety of features, including hunting ability, companionship, intelligence, herding ability, and looks. Interestingly, there are over four hundred dog breeds today, and most of them were developed in just the last 150 years. This shows a remarkably rapid evolution of a great number of different dog breeds. Most of these breeds were made by first taking two very different existing dog breeds and crossing them. This maximizes genetic diversity in the offspring. Then there is a systematic selection, choosing the pick of the litter, those animals with the desired characteristics, and interbreeding them to make the next generation. The continued brother-sister matings coupled with continued selection rapidly results in a new breed of dog with a new set of characteristics. The new breed is genetically pure, because the repeated inbreeding removes genetic diversity. And the new dog can have a very distinctive set of features because of the artificial systematic selection for those very features. The Doberman pinscher, the Australian cattle dog, and the whippet were all developed in this manner.

It is remarkable to consider that the wolf had enough genetic diversity in its DNA to give rise to all of the dog breeds we see today. Wolves all look pretty much alike, and you’d think that if you keep breeding wolves you’d just get more wolves. Yet there are actually millions of base differences in the DNAs of different wolves, among the billions of bases total. This is clearly sufficient diversity to produce progeny with quite distinct traits when the power of artificial selection is applied over many generations.

The dog story is an interesting demonstration of evolution at work. In an extremely short period of time, in evolutionary terms, the wolf evolved into the dog, including all of the great variety of dog types we have today. This is one evolutionary event that was not only watched by man, but indeed was driven by man. It is but one example of the many domestic animals and plants that illustrate the incredible power of artificial selection.

Darwin proposed that given enough time the forces of natural selection could change the traits of species. The neck of the giraffe would get longer, to reach more vegetation, the gazelle could get faster, to better escape, and the cheetah could get faster, to better catch the gazelle.

The artificial selection that drove the evolution of dogs is simply natural selection on steroids. It proves the principle, and shows without a doubt that evolution is true.

About the author. Steven Potter, PhD, is a Professor of Pediatrics, in the Division of Developmental Biology, at Children’s Hospital Medical Center in Cincinnati. He has authored Designer Genes: A New Era in the Evolution of Man, published by Random House http://www.amazon.com/Designer-Genes-New-Era-Evolution/dp/140006905X/ref=sr_1_1?ie=UTF8&s=books&qid=1303812945&sr=1-1. He has also written over one hundred science papers and co-authored the third edition of the medical school textbook, Larsen’s Human Embryology.

Why Yamanaka Will Win the Nobel Prize

Stem cells are almost magical in their power. It is possible to turn stem cells into all other cell types of the body, including brain, heart and kidney. This is why they offer so much promise for the regeneration and repair of diseased and damaged organs. But the most powerful stem cells, those able to make the most cell types, have historically come from early embryos. Hence the ethical controversy, since it has been necessary to kill human embryos to make human stem cells.

Yamanaka changed all of that. He discovered a way to take adult cells, for example from the skin, and to turn them into extremely potent stem cells, indeed able to give rise to all cell types. This discovery has absolutely revolutionized stem cell research. We don’t need stem cells from human embryos anymore, so the key ethical objections to this research have been eliminated. And now it is possible to take skin cells from a patient and to make stem cells that are an exact genetic match. This means that there would no longer be any immune rejection problems for stem cell treatments.

How is it done? How can we convert a differentiated adult cell into the functional equivalent of a cell from a very early embryo? The answer lies in the manipulation of gene expression patterns.

When an egg is fertilized by a sperm their two sets of genes are united, creating the unique genetic combination of that individual. During development, as that single cell, the fertilized egg, proceeds to make a person, exact copies of every gene are made before every cell division. The end result is that every cell of the body carries the same complement of genes. But different cell types use their genes differently. Brain cells will have a set of brain genes active, while a liver cell will have a unique combination of liver genes active. The cell is sort of like a computer. It carries many gene programs capable of doing many different things, but only uses one program at a time.

But not all genes are created equal. Some are much more powerful than others. Fruit fly geneticists discovered about 100 years ago that mutations in some genes had amazingly profound effects. For example, an alteration of a gene named Antennapedia resulted in a fruit fly that had legs coming out of the head where the antennae were supposed to be! What a crazy fly, with an extra pair of legs coming out of its head. Mutation of another gene, bicoid, gave a true butt head fly, with an extra butt where its head was supposed to be. Genes of this sort were dubbed master switch genetic regulators because of their incredible effects.

How do they do it? These genes function by regulating the activities of other genes. And some of the genes they activate are additional regulator genes. It is easy to see how switching on one of these genes can initiate a genetic cascade, changing the expression levels of hundreds or even thousands of downstream genes, thereby controlling the developmental destinies of cells.

The genius of Yamanaka was to realize that there might be such master switch genes capable of converting adult cells into stem cells. Who would think this is possible? Turning a skin cell, for example, into the equivalent of an embryonic cell! But Yamanaka proved it was indeed possible. It was technically very challenging because a special combination of four master switch genes had to be turned on simultaneously to make it happen. Figuring out how many were necessary, and which ones, out of the over twenty thousand genes present, was a technical tour de force. But, to his great credit, he and his coworkers did it.

And so the stem cell revolution takes a giant leap forward. You need a bone marrow transplant? Why not be your own perfectly matched donor? Take skin cells, turn them into embryonic stem cells and then convert those into blood stem cells. Maybe you need a complete replacement organ, like a heart, liver or kidney. Remarkable progress is being made in turning stem cells into organs. Further, think quadriplegics that can walk again, the blind that can see again, the deaf that can hear again, and a cure for diabetes. We are clearly at the beginning stage of a new era in medicine. Doctors of the future will have a new set of mind-boggling tools for the treatment of a host of diseases involving diseased or worn out organs.

This is why Yamanaka will win the Nobel Prize.

About the Author: Steve Potter, PhD, is a Professor of Pediatrics, in the Division of Developmental Biology, at Children’s Hospital Medical Center in Cincinnati. He has authored Designer Genes: A New Era in the Evolution of Man, published by Random House 2010 http://www.amazon.com/Designer-Genes-New-Era-Evolution/dp/140006905X/ref=sr_1_1?ie=UTF8&s=books&qid=1303812945&sr=1-1
. In addition he has written over one hundred science papers, and co-authored the third edition of the medical school textbook, Larsen’s Human Embryology.

Eveloce: A term coined in Designer Genes: A New Era in the Evolution of Man. It refers to self accelerating evolution. For example, in the not too distant future people will be able to genetically engineer offspring with increased intelligence, who in turn will be better equipped to make offspring that are still smarter. It is easy to see how this kind of evolution could go explosive.

 

Radical Cloning

There is a quiet revolution going on in the world of cloning.  Very few have heard of it, but its potential power is astonishing. Imagine a radical new way to clone that can not only create exact carbon copies of adults, but also allows the generation of important genetic improvements. Another you, but smarter, healthier, and maybe a bit better looking.

The birth of Dolly the sheep fifteen years ago shocked the world. We learned it is possible to replace the genes of an egg with those from an adult, and in a few cases the egg would proceed to make a viable clone, like Dolly. And the debates began! Should we allow human cloning? Was this a useful new reproductive option for childless couples? Or was it a crime against nature? Would clones have a soul? Were we moving towards a Brave New World future, with armies of clones fighting our wars and working in our factories?

The gene replacement technology used to make Dolly, however, was severely flawed. Only about one in a hundred eggs with genes from an adult survives. This procedure clearly should not be applied to people. For every birth there would be 99 aborted monstrosities, and even the rare clones surviving to birth are not really normal when examined carefully.

But recently we’ve seen a perfect storm of incredible advances in biology that changes everything. It is now possible to take adult cells, from the skin for example, and to transform them into stem cells, which can then be converted into complete individuals. It works quite well for mice, and there is every reason to think it would also work for humans.

How is this cloning through stem cells accomplished? The breakthrough was Shinya Yamanaka’s discovery that it is possible to treat adult cells with a special gene expression cocktail that turns them into the functional equivalent of embryonic stem cells. Stem cells, as the name suggests, are able to branch in many different developmental directions, to give rise to heart, nerve, liver, or other cell types. In the field of medicine, this is like the ancient alchemist somehow succeeding in turning lead into gold. Stem cells offer great promise in the regeneration and repair of diseased or damaged organs. Historically, the most powerful stem cells – those able to give rise to all of the different cell types of the body – were made from embryos. Hence the ethical controversy, since it was necessary to kill human embryos to make embryonic stem cells.

Adult derived stem cells made by the Yamanaka procedure, however, are as powerful as those made from embryos. They too can give rise to all of the cell types of the body. Indeed, it is possible to take adult derived mouse stem cells, grown in a plastic dish in the laboratory, and to turn them into complete mice. The controversy over human embryonic stem cells should now be officially over because we can make equally potent stem cells from adults, without sacrificing embryos.

Stem cell cloning, however, opens a Pandora’s box of possibilities.  It is much more efficient than the gene replacement approach used to make Dolly. In addition, stem cells are extremely genetically malleable. Nobel prize winning genetic engineering technology works very well with them. It is therefore now feasible to clone not only exact copies, but also improved versions of people.

With the technical objections rapidly fading, it is now time to revisit the ethical issues of cloning. First, is it morally wrong to have multiple people with the same, or nearly the same, genes? Of course identical twins, triplets, quadruplets, and so on have long existed as a product of nature.  But there are some differences between clones and twins. Twins are the same age, while a clone would be younger than its single parent. In addition, there is a limit on the number of genetically identical individuals that can be made by natural reproduction, but in theory a hundred or more clones could be made from one person. It makes most of us uncomfortable to think that a wealthy person could now make many young copies of him or herself.

Another issue is procreation without sex. Some people find the laboratory creation of human offspring repugnant, thinking it degrades and cheapens the process of reproduction. Are we heading towards a shopping catalog selection of our children? Nevertheless, the current methods of in vitro fertilization involve mixing eggs and sperm in the test tube, thereby creating human embryos for otherwise infertile couples. About one percent of all births in the U.S. are now the result of in vitro fertilization. Cloning technology is similar in principle, but using only one parent to make embryos instead of two. Does that difference make it morally wrong?

Our science and technology are marching forward at an ever accelerating pace. The topic could not be more important. We are talking about the nature of our children, and in the long run, our species. Genetic enhancement could lead to improved intelligence, and exceptionally long and healthy lives. Or a hellish dystopia. We must move into the future with great care.

About the Author: Steve Potter is a Professor of Pediatrics, in the Division of Developmental Biology, at Children’s Hospital Medical Center in Cincinnati. He is the author of Designer Genes: A New Era in the Evolution of Man, published by Random House, 2010. In addition he has written over one hundred science papers, and co-authored the third edition of the medical school textbook, Larsen’s Human Embryology.

Eveloce: A term coined in Designer Genes: A New Era in the Evolution of Man. It refers to self accelerating evolution. For example, in the not too distant future people will be able to genetically engineer offspring with increased intelligence, who in turn will be better equipped to make offspring that are still smarter. It is easy to see how this kind of evolution could go explosive.